The present invention relates to a cable tray and more particularly to a cable tray with readily removable and replaceable rungs while in service.
Cable trays are devices mounted on walls or suspended from ceilings for carrying cables such as for communications, computers, power transmission, etc.
Cable trays now in use suffer a variety drawbacks. Their construction very often is complex or expensive. All of them lack the ability to alter their capacity once in place, are difficult to mount in tight locations, are impossible to replace damaged rungs, or to change the length of a rung when required.
A number of United States Patents have been issued which show designs of cable trays now in use or known.
U.S. Pat. No. 3,042,351 discloses a basket shaped tray in which lengths are joined in a novel connecting arrangement.
U.S. Pat. No. 3,363,048 shows a cable supporting tray employing a central spine with rungs going through spines and crimped into place at top of the spines.
U.S. Pat. No. 3,915,420 describes a cable tray made of ladder-like sections which are interlocked together.
U.S. Pat. No. 3,948,473 discloses a universal cable rack made of extended side stringers on top of which are mounted crossover members.
U.S. Pat. No. 5,004,194 describes a side supported cable tray made of sheet metal formed into a U-shape using slots to support the edges of a side wall which is adjustable.
None of the preceding patents teaches the present invention.